Jilin Provincial Key Laboratory of Nutrition and Functional Food, Jilin University, Changchun 130062, China; College of Food Science and Engineering, Jilin University, Changchun 130062, China.
Jilin Provincial Key Laboratory of Nutrition and Functional Food, Jilin University, Changchun 130062, China; College of Food Science and Engineering, Jilin University, Changchun 130062, China.
Int J Biol Macromol. 2023 Dec 31;253(Pt 1):126487. doi: 10.1016/j.ijbiomac.2023.126487. Epub 2023 Aug 30.
This study aims to investigate the mechanism of magnesium ions regulated ovalbumin-lysozyme (OVA-LYS) heteroprotein aggregation behavior via aggregation kinetics model, exploring the relationship between differential aggregation behavior and protein molecular structure, intermolecular interactions and thermal stability. Results showed that the aggregation rate (k) and maximum absorbance (A) of the OVA-LYS heteroprotein complex were located between OVA and LYS. Meanwhile, the thermal denaturation temperature (Td) and denaturation enthalpy (ΔH) were between the values of OVA and LYS as well. Compared with OVA, the thermal stability of the OVA-LYS heteroprotein complex increased owing to the electrostatic interactions between OVA and LYS, resulting in slower aggregation rate and lower aggregation degree. Molecular dynamics simulations revealed the molecular conformational changes during OVA-LYS binary protein binding and the stability of the complex conformation. Moreover, MgCl weakened the OVA-LYS interactions through Debye shielding while increasing thermal stability, allowing the two proteins to aggregate into amorphous precipitates rather than spherical coacervates. Overall, this study provides information to further understand the regulation mechanism of proteins differential aggregation behavior by ions.
本研究旨在通过聚集动力学模型研究镁离子调控卵清蛋白-溶菌酶（OVA-LYS）杂合蛋白聚集行为的机制，探索差异聚集行为与蛋白质分子结构、分子间相互作用和热稳定性之间的关系。结果表明，OVA-LYS 杂合蛋白复合物的聚集速率（k）和最大吸光度（A）位于 OVA 和 LYS 之间。同时，OVA-LYS 杂合蛋白复合物的热变性温度（Td）和变性焓（ΔH）也介于 OVA 和 LYS 的值之间。与 OVA 相比，由于 OVA 和 LYS 之间的静电相互作用，OVA-LYS 杂合蛋白复合物的热稳定性增加，导致聚合速率较慢，聚合程度较低。分子动力学模拟揭示了 OVA-LYS 二元蛋白结合过程中分子构象的变化以及复合物构象的稳定性。此外，MgCl 通过德拜屏蔽减弱了 OVA-LYS 相互作用，同时增加了热稳定性，使两种蛋白质聚集成无定形沉淀物而不是球形凝聚物。总的来说，本研究提供了信息，以进一步了解离子对蛋白质差异聚集行为的调节机制。
